As the use of neural stimulating electrodes has incresased, more attention has been directed towards studying possible adverse side effects attendant to their use. This is especially true for applications which require schronic stimulation of high current densities. The risk of tissue damage, which is generally believed to be associated with the toxic species formed electrochemically at the electrode tissue interface, has been hindering the progress in neural stimulation. The objective of this proposed program is to develop high surface area "double layer" type stimulating electrodes suitable for the electrical stimulation of neural elements and thus contribute to the development of electrical devices for treatment of various neurological disorders. Specifically, we plan to prepare and characterize high surface area carbon and gold microelectrodes. In addition, we propose to demonstrate their operating modes experimentally. After successful long-term IN-VITRO testing, these micro-stimulating electrodes will be fabricated and delivered to NIH-NINCDS in the form of completely finished micro-stimulting electrode assemblies in Phase II for IN-VIVO testing.